Situations where personal objects should be carried or not, depending in particular upon the day of the week, the time, and the person, arise very often. Typical example situations are:                a person arrives in the office in the morning, and realizes that he/she forgot to take his/her company badge;        a person arrives in the office in the morning, and realizes that he/she missed to take his/her office room key ring;        a person leaves his home to pick up his car in the garage and realizes that he forgot to take the car keys;        a person leaves his home to drive to the office and realizes in the office that he holds the key of the car his wife drives; and,        a person arrives at the tennis court and realizes that he forgot to take his racket.        
Plenty of similar example situations exist where required personal objects are not carried or where undesired personal objects are carried.
U.S. Pat. No. 6,462,660 discloses a system and method of reminding a user of any missing portable electronic devices when leaving a location. A reminder device transmits a signal to each of the reminder enabled devices. The reminder device then alerts the user of any reminder enabled devices that did not transmit acknowledgment signals.
If the system disclosed in U.S. Pat. No. 6,462,660 is efficient for alerting a user of missing devices, it is not adapted to handle complex situations, in particular situations where a plurality of users handle different objects.
Thus, there is a need for a method and systems for checking the presence and absence of personal objects in a complex environment with multiple users.